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+gittutorial(7)
+==============
+
+NAME
+----
+gittutorial - A tutorial introduction to Git
+
+SYNOPSIS
+--------
+[verse]
+git *
+
+DESCRIPTION
+-----------
+
+This tutorial explains how to import a new project into Git, make
+changes to it, and share changes with other developers.
+
+If you are instead primarily interested in using Git to fetch a project,
+for example, to test the latest version, you may prefer to start with
+the first two chapters of link:user-manual.html[The Git User's Manual].
+
+First, note that you can get documentation for a command such as
+`git log --graph` with:
+
+------------------------------------------------
+$ man git-log
+------------------------------------------------
+
+or:
+
+------------------------------------------------
+$ git help log
+------------------------------------------------
+
+With the latter, you can use the manual viewer of your choice; see
+linkgit:git-help[1] for more information.
+
+It is a good idea to introduce yourself to Git with your name and
+public email address before doing any operation.  The easiest
+way to do so is:
+
+------------------------------------------------
+$ git config --global user.name "Your Name Comes Here"
+$ git config --global user.email you@yourdomain.example.com
+------------------------------------------------
+
+
+Importing a new project
+-----------------------
+
+Assume you have a tarball project.tar.gz with your initial work.  You
+can place it under Git revision control as follows.
+
+------------------------------------------------
+$ tar xzf project.tar.gz
+$ cd project
+$ git init
+------------------------------------------------
+
+Git will reply
+
+------------------------------------------------
+Initialized empty Git repository in .git/
+------------------------------------------------
+
+You've now initialized the working directory--you may notice a new
+directory created, named ".git".
+
+Next, tell Git to take a snapshot of the contents of all files under the
+current directory (note the '.'), with 'git add':
+
+------------------------------------------------
+$ git add .
+------------------------------------------------
+
+This snapshot is now stored in a temporary staging area which Git calls
+the "index".  You can permanently store the contents of the index in the
+repository with 'git commit':
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
+This will prompt you for a commit message.  You've now stored the first
+version of your project in Git.
+
+Making changes
+--------------
+
+Modify some files, then add their updated contents to the index:
+
+------------------------------------------------
+$ git add file1 file2 file3
+------------------------------------------------
+
+You are now ready to commit.  You can see what is about to be committed
+using 'git diff' with the --cached option:
+
+------------------------------------------------
+$ git diff --cached
+------------------------------------------------
+
+(Without --cached, 'git diff' will show you any changes that
+you've made but not yet added to the index.)  You can also get a brief
+summary of the situation with 'git status':
+
+------------------------------------------------
+$ git status
+On branch master
+Changes to be committed:
+Your branch is up to date with 'origin/master'.
+  (use "git restore --staged <file>..." to unstage)
+
+	modified:   file1
+	modified:   file2
+	modified:   file3
+
+------------------------------------------------
+
+If you need to make any further adjustments, do so now, and then add any
+newly modified content to the index.  Finally, commit your changes with:
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
+This will again prompt you for a message describing the change, and then
+record a new version of the project.
+
+Alternatively, instead of running 'git add' beforehand, you can use
+
+------------------------------------------------
+$ git commit -a
+------------------------------------------------
+
+which will automatically notice any modified (but not new) files, add
+them to the index, and commit, all in one step.
+
+A note on commit messages: Though not required, it's a good idea to
+begin the commit message with a single short (less than 50 character)
+line summarizing the change, followed by a blank line and then a more
+thorough description. The text up to the first blank line in a commit
+message is treated as the commit title, and that title is used
+throughout Git.  For example, linkgit:git-format-patch[1] turns a
+commit into email, and it uses the title on the Subject line and the
+rest of the commit in the body.
+
+Git tracks content not files
+----------------------------
+
+Many revision control systems provide an `add` command that tells the
+system to start tracking changes to a new file.  Git's `add` command
+does something simpler and more powerful: 'git add' is used both for new
+and newly modified files, and in both cases it takes a snapshot of the
+given files and stages that content in the index, ready for inclusion in
+the next commit.
+
+Viewing project history
+-----------------------
+
+At any point you can view the history of your changes using
+
+------------------------------------------------
+$ git log
+------------------------------------------------
+
+If you also want to see complete diffs at each step, use
+
+------------------------------------------------
+$ git log -p
+------------------------------------------------
+
+Often the overview of the change is useful to get a feel of
+each step
+
+------------------------------------------------
+$ git log --stat --summary
+------------------------------------------------
+
+Managing branches
+-----------------
+
+A single Git repository can maintain multiple branches of
+development.  To create a new branch named "experimental", use
+
+------------------------------------------------
+$ git branch experimental
+------------------------------------------------
+
+If you now run
+
+------------------------------------------------
+$ git branch
+------------------------------------------------
+
+you'll get a list of all existing branches:
+
+------------------------------------------------
+  experimental
+* master
+------------------------------------------------
+
+The "experimental" branch is the one you just created, and the
+"master" branch is a default branch that was created for you
+automatically.  The asterisk marks the branch you are currently on;
+type
+
+------------------------------------------------
+$ git switch experimental
+------------------------------------------------
+
+to switch to the experimental branch.  Now edit a file, commit the
+change, and switch back to the master branch:
+
+------------------------------------------------
+(edit file)
+$ git commit -a
+$ git switch master
+------------------------------------------------
+
+Check that the change you made is no longer visible, since it was
+made on the experimental branch and you're back on the master branch.
+
+You can make a different change on the master branch:
+
+------------------------------------------------
+(edit file)
+$ git commit -a
+------------------------------------------------
+
+at this point the two branches have diverged, with different changes
+made in each.  To merge the changes made in experimental into master, run
+
+------------------------------------------------
+$ git merge experimental
+------------------------------------------------
+
+If the changes don't conflict, you're done.  If there are conflicts,
+markers will be left in the problematic files showing the conflict;
+
+------------------------------------------------
+$ git diff
+------------------------------------------------
+
+will show this.  Once you've edited the files to resolve the
+conflicts,
+
+------------------------------------------------
+$ git commit -a
+------------------------------------------------
+
+will commit the result of the merge. Finally,
+
+------------------------------------------------
+$ gitk
+------------------------------------------------
+
+will show a nice graphical representation of the resulting history.
+
+At this point you could delete the experimental branch with
+
+------------------------------------------------
+$ git branch -d experimental
+------------------------------------------------
+
+This command ensures that the changes in the experimental branch are
+already in the current branch.
+
+If you develop on a branch crazy-idea, then regret it, you can always
+delete the branch with
+
+-------------------------------------
+$ git branch -D crazy-idea
+-------------------------------------
+
+Branches are cheap and easy, so this is a good way to try something
+out.
+
+Using Git for collaboration
+---------------------------
+
+Suppose that Alice has started a new project with a Git repository in
+/home/alice/project, and that Bob, who has a home directory on the
+same machine, wants to contribute.
+
+Bob begins with:
+
+------------------------------------------------
+bob$ git clone /home/alice/project myrepo
+------------------------------------------------
+
+This creates a new directory "myrepo" containing a clone of Alice's
+repository.  The clone is on an equal footing with the original
+project, possessing its own copy of the original project's history.
+
+Bob then makes some changes and commits them:
+
+------------------------------------------------
+(edit files)
+bob$ git commit -a
+(repeat as necessary)
+------------------------------------------------
+
+When he's ready, he tells Alice to pull changes from the repository
+at /home/bob/myrepo.  She does this with:
+
+------------------------------------------------
+alice$ cd /home/alice/project
+alice$ git pull /home/bob/myrepo master
+------------------------------------------------
+
+This merges the changes from Bob's "master" branch into Alice's
+current branch.  If Alice has made her own changes in the meantime,
+then she may need to manually fix any conflicts.
+
+The "pull" command thus performs two operations: it fetches changes
+from a remote branch, then merges them into the current branch.
+
+Note that in general, Alice would want her local changes committed before
+initiating this "pull".  If Bob's work conflicts with what Alice did since
+their histories forked, Alice will use her working tree and the index to
+resolve conflicts, and existing local changes will interfere with the
+conflict resolution process (Git will still perform the fetch but will
+refuse to merge --- Alice will have to get rid of her local changes in
+some way and pull again when this happens).
+
+Alice can peek at what Bob did without merging first, using the "fetch"
+command; this allows Alice to inspect what Bob did, using a special
+symbol "FETCH_HEAD", in order to determine if he has anything worth
+pulling, like this:
+
+------------------------------------------------
+alice$ git fetch /home/bob/myrepo master
+alice$ git log -p HEAD..FETCH_HEAD
+------------------------------------------------
+
+This operation is safe even if Alice has uncommitted local changes.
+The range notation "HEAD..FETCH_HEAD" means "show everything that is reachable
+from the FETCH_HEAD but exclude anything that is reachable from HEAD".
+Alice already knows everything that leads to her current state (HEAD),
+and reviews what Bob has in his state (FETCH_HEAD) that she has not
+seen with this command.
+
+If Alice wants to visualize what Bob did since their histories forked
+she can issue the following command:
+
+------------------------------------------------
+$ gitk HEAD..FETCH_HEAD
+------------------------------------------------
+
+This uses the same two-dot range notation we saw earlier with 'git log'.
+
+Alice may want to view what both of them did since they forked.
+She can use three-dot form instead of the two-dot form:
+
+------------------------------------------------
+$ gitk HEAD...FETCH_HEAD
+------------------------------------------------
+
+This means "show everything that is reachable from either one, but
+exclude anything that is reachable from both of them".
+
+Please note that these range notation can be used with both gitk
+and "git log".
+
+After inspecting what Bob did, if there is nothing urgent, Alice may
+decide to continue working without pulling from Bob.  If Bob's history
+does have something Alice would immediately need, Alice may choose to
+stash her work-in-progress first, do a "pull", and then finally unstash
+her work-in-progress on top of the resulting history.
+
+When you are working in a small closely knit group, it is not
+unusual to interact with the same repository over and over
+again.  By defining 'remote' repository shorthand, you can make
+it easier:
+
+------------------------------------------------
+alice$ git remote add bob /home/bob/myrepo
+------------------------------------------------
+
+With this, Alice can perform the first part of the "pull" operation
+alone using the 'git fetch' command without merging them with her own
+branch, using:
+
+-------------------------------------
+alice$ git fetch bob
+-------------------------------------
+
+Unlike the longhand form, when Alice fetches from Bob using a
+remote repository shorthand set up with 'git remote', what was
+fetched is stored in a remote-tracking branch, in this case
+`bob/master`.  So after this:
+
+-------------------------------------
+alice$ git log -p master..bob/master
+-------------------------------------
+
+shows a list of all the changes that Bob made since he branched from
+Alice's master branch.
+
+After examining those changes, Alice
+could merge the changes into her master branch:
+
+-------------------------------------
+alice$ git merge bob/master
+-------------------------------------
+
+This `merge` can also be done by 'pulling from her own remote-tracking
+branch', like this:
+
+-------------------------------------
+alice$ git pull . remotes/bob/master
+-------------------------------------
+
+Note that git pull always merges into the current branch,
+regardless of what else is given on the command line.
+
+Later, Bob can update his repo with Alice's latest changes using
+
+-------------------------------------
+bob$ git pull
+-------------------------------------
+
+Note that he doesn't need to give the path to Alice's repository;
+when Bob cloned Alice's repository, Git stored the location of her
+repository in the repository configuration, and that location is
+used for pulls:
+
+-------------------------------------
+bob$ git config --get remote.origin.url
+/home/alice/project
+-------------------------------------
+
+(The complete configuration created by 'git clone' is visible using
+`git config -l`, and the linkgit:git-config[1] man page
+explains the meaning of each option.)
+
+Git also keeps a pristine copy of Alice's master branch under the
+name "origin/master":
+
+-------------------------------------
+bob$ git branch -r
+  origin/master
+-------------------------------------
+
+If Bob later decides to work from a different host, he can still
+perform clones and pulls using the ssh protocol:
+
+-------------------------------------
+bob$ git clone alice.org:/home/alice/project myrepo
+-------------------------------------
+
+Alternatively, Git has a native protocol, or can use http;
+see linkgit:git-pull[1] for details.
+
+Git can also be used in a CVS-like mode, with a central repository
+that various users push changes to; see linkgit:git-push[1] and
+linkgit:gitcvs-migration[7].
+
+Exploring history
+-----------------
+
+Git history is represented as a series of interrelated commits.  We
+have already seen that the 'git log' command can list those commits.
+Note that first line of each git log entry also gives a name for the
+commit:
+
+-------------------------------------
+$ git log
+commit c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
+Author: Junio C Hamano <junkio@cox.net>
+Date:   Tue May 16 17:18:22 2006 -0700
+
+    merge-base: Clarify the comments on post processing.
+-------------------------------------
+
+We can give this name to 'git show' to see the details about this
+commit.
+
+-------------------------------------
+$ git show c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
+-------------------------------------
+
+But there are other ways to refer to commits.  You can use any initial
+part of the name that is long enough to uniquely identify the commit:
+
+-------------------------------------
+$ git show c82a22c39c	# the first few characters of the name are
+			# usually enough
+$ git show HEAD		# the tip of the current branch
+$ git show experimental	# the tip of the "experimental" branch
+-------------------------------------
+
+Every commit usually has one "parent" commit
+which points to the previous state of the project:
+
+-------------------------------------
+$ git show HEAD^  # to see the parent of HEAD
+$ git show HEAD^^ # to see the grandparent of HEAD
+$ git show HEAD~4 # to see the great-great grandparent of HEAD
+-------------------------------------
+
+Note that merge commits may have more than one parent:
+
+-------------------------------------
+$ git show HEAD^1 # show the first parent of HEAD (same as HEAD^)
+$ git show HEAD^2 # show the second parent of HEAD
+-------------------------------------
+
+You can also give commits names of your own; after running
+
+-------------------------------------
+$ git tag v2.5 1b2e1d63ff
+-------------------------------------
+
+you can refer to 1b2e1d63ff by the name "v2.5".  If you intend to
+share this name with other people (for example, to identify a release
+version), you should create a "tag" object, and perhaps sign it; see
+linkgit:git-tag[1] for details.
+
+Any Git command that needs to know a commit can take any of these
+names.  For example:
+
+-------------------------------------
+$ git diff v2.5 HEAD	 # compare the current HEAD to v2.5
+$ git branch stable v2.5 # start a new branch named "stable" based
+			 # at v2.5
+$ git reset --hard HEAD^ # reset your current branch and working
+			 # directory to its state at HEAD^
+-------------------------------------
+
+Be careful with that last command: in addition to losing any changes
+in the working directory, it will also remove all later commits from
+this branch.  If this branch is the only branch containing those
+commits, they will be lost.  Also, don't use 'git reset' on a
+publicly-visible branch that other developers pull from, as it will
+force needless merges on other developers to clean up the history.
+If you need to undo changes that you have pushed, use 'git revert'
+instead.
+
+The 'git grep' command can search for strings in any version of your
+project, so
+
+-------------------------------------
+$ git grep "hello" v2.5
+-------------------------------------
+
+searches for all occurrences of "hello" in v2.5.
+
+If you leave out the commit name, 'git grep' will search any of the
+files it manages in your current directory.  So
+
+-------------------------------------
+$ git grep "hello"
+-------------------------------------
+
+is a quick way to search just the files that are tracked by Git.
+
+Many Git commands also take sets of commits, which can be specified
+in a number of ways.  Here are some examples with 'git log':
+
+-------------------------------------
+$ git log v2.5..v2.6            # commits between v2.5 and v2.6
+$ git log v2.5..                # commits since v2.5
+$ git log --since="2 weeks ago" # commits from the last 2 weeks
+$ git log v2.5.. Makefile       # commits since v2.5 which modify
+				# Makefile
+-------------------------------------
+
+You can also give 'git log' a "range" of commits where the first is not
+necessarily an ancestor of the second; for example, if the tips of
+the branches "stable" and "master" diverged from a common
+commit some time ago, then
+
+-------------------------------------
+$ git log stable..master
+-------------------------------------
+
+will list commits made in the master branch but not in the
+stable branch, while
+
+-------------------------------------
+$ git log master..stable
+-------------------------------------
+
+will show the list of commits made on the stable branch but not
+the master branch.
+
+The 'git log' command has a weakness: it must present commits in a
+list.  When the history has lines of development that diverged and
+then merged back together, the order in which 'git log' presents
+those commits is meaningless.
+
+Most projects with multiple contributors (such as the Linux kernel,
+or Git itself) have frequent merges, and 'gitk' does a better job of
+visualizing their history.  For example,
+
+-------------------------------------
+$ gitk --since="2 weeks ago" drivers/
+-------------------------------------
+
+allows you to browse any commits from the last 2 weeks of commits
+that modified files under the "drivers" directory.  (Note: you can
+adjust gitk's fonts by holding down the control key while pressing
+"-" or "+".)
+
+Finally, most commands that take filenames will optionally allow you
+to precede any filename by a commit, to specify a particular version
+of the file:
+
+-------------------------------------
+$ git diff v2.5:Makefile HEAD:Makefile.in
+-------------------------------------
+
+You can also use 'git show' to see any such file:
+
+-------------------------------------
+$ git show v2.5:Makefile
+-------------------------------------
+
+Next Steps
+----------
+
+This tutorial should be enough to perform basic distributed revision
+control for your projects.  However, to fully understand the depth
+and power of Git you need to understand two simple ideas on which it
+is based:
+
+  * The object database is the rather elegant system used to
+    store the history of your project--files, directories, and
+    commits.
+
+  * The index file is a cache of the state of a directory tree,
+    used to create commits, check out working directories, and
+    hold the various trees involved in a merge.
+
+Part two of this tutorial explains the object
+database, the index file, and a few other odds and ends that you'll
+need to make the most of Git. You can find it at linkgit:gittutorial-2[7].
+
+If you don't want to continue with that right away, a few other
+digressions that may be interesting at this point are:
+
+  * linkgit:git-format-patch[1], linkgit:git-am[1]: These convert
+    series of git commits into emailed patches, and vice versa,
+    useful for projects such as the Linux kernel which rely heavily
+    on emailed patches.
+
+  * linkgit:git-bisect[1]: When there is a regression in your
+    project, one way to track down the bug is by searching through
+    the history to find the exact commit that's to blame.  Git bisect
+    can help you perform a binary search for that commit.  It is
+    smart enough to perform a close-to-optimal search even in the
+    case of complex non-linear history with lots of merged branches.
+
+  * linkgit:gitworkflows[7]: Gives an overview of recommended
+    workflows.
+
+  * linkgit:giteveryday[7]: Everyday Git with 20 Commands Or So.
+
+  * linkgit:gitcvs-migration[7]: Git for CVS users.
+
+SEE ALSO
+--------
+linkgit:gittutorial-2[7],
+linkgit:gitcvs-migration[7],
+linkgit:gitcore-tutorial[7],
+linkgit:gitglossary[7],
+linkgit:git-help[1],
+linkgit:gitworkflows[7],
+linkgit:giteveryday[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite